Controlling the red LED in the thinkpad logo (T440s)

[yak_sk]

Has anyone managed to control (turn on / off / blink) the red led in the letter 'i' in the ThinkPad logo that comes with the new
lenovo thinkpad series? (T440s in particular)

I have tried all the numbers in

echo 'i blink' > /proc/acpi/ibm/led
where i is a number between 0 and 15.

and

echo '1|0' > /sys/devices/platform/thinkpad_acpi/leds/ ... / brightness
where ... is the led device name

But none of those combinations were this particular LED. Can this be controlled? I'm using the 3.12.13-gentoo kernel,
but I am willing to upgrade/switc/patch.